code: def __init__(self, **kwargs):
      raise Exception(
          "dash[testing] was not installed. "
          "Please install to use the dash testing fixtures."
      )
  
file_path: dash/dash/testing/plugin.py
imports: import pytest
  from .consts import SELENIUM_GRID_DEFAULT
label_desc: Use image node_id 1 to create a new MissingDashTesting object  with example: obj = MissingDashTesting()